What is a Bar Clamp Used For

What is a Bar Clamp Used For?

We’ve written previously about clamps and clamping wood being joined with glue. Among the clamps, we wrote about in that piece is the bar clamp, an indispensable clamp in your woodworking shop if you are going to be making a new tabletop, door, cabinet, or box.

Bar clamps, also known as F clamps because of their shape, have a long metal bar (thus, the name) with 2 adjustable arms that you can move to the appropriate dimension of the workpiece being clamped.  For example, let’s say your dining room tabletop you’re making is 30 inches and consists of three 10” pieces of wood being glued together.  You’d adjust the arms to fit that 30” span and tighten the clamp accordingly.  If the length of the boards is 6”, you’ll likely want to use 4 bar clamps along that length, so the pressure was evenly exerted along the span. 

The ability to expand and contract the arms makes bar clamps very versatile and usable on long and wide spans.  They are measured by their jaw opening, which determines the size of the workpiece being clamped.  Your shop should have a variety of sizes to accommodate all of the projects you anticipate taking on.

How Does A Bar Clamp Work?

As noted, the arms on a bar clamp are adjustable along the metal bar.  One of the arms is fixed and does not move.  This arm, known as the head jaw, has a large, threaded screw that is tightened to firm up the clamp’s hold on the workpiece and loosened when the clamp is being removed.

The other arm is known as the jaw arm or back jaw.  This arm is moved along the metal bar to fit the object and then secured into place by an adjustable screw.  The head jaw then tightens the clamp to apply the desired pressure on the workpiece, and it is left to do its job.

Bar Clamp

Some bar clamps have a quick-release lever for convenience.  You can imagine how handy a quick-release bar clamp can be for repetitive tasks on your workpiece or for a quick adjustment in the placement of the bar clamp on it.

You can also buy metal bar extensions that fit into place the way curtain rods, for instance, can be extended to fit the size of your windows.  This increases the versatility of bar clamps to accommodate larger workpieces as well as smaller ones and saves a little money in the process.  Bar clamps can be expensive, so saving a few dollars by having an extension handy for a wider tabletop, for instance, can stretch your workshop budget.

There are different types of bar clamps, too, including T-bar clamps, pipe clamps, and the aforementioned quick-release bar clamps.  In a smaller size, you will also find ratchet bar clamps, very convenient for small jobs.  They are exactly what the name implies – the adjustments and tightening are made by ratcheting the arms to the desired size.

As handy as bar clamps are for applying pressure to gluing-up workpieces, they do have downsides.  They are not well-suited in workshops with limited space because the metal arms are long, and, because of their size, they are not well-suited for smaller pieces like a small drawer or box because either the arms are too long or the jaws are too big.  For these types of projects, you would want to consider a smaller ratchet bar clamp or a C-clamp.

C-clamps, for instance, come in a wide variety of sizes that range from ¾ inch to 14 inches.  They do require a little more work to set in place than a bar clamp, but they are also effective in small glue-up projects.

But for heavy-duty clamping, you can’t beat the bar clamp.  They are strong and sturdy, easy to work with and do the job well.  And for extra heavy-duty clamping, the pipe clamp might be an even better choice.  Threaded pipe pieces that can be joined together for large glue-ups are akin to the extensions available for bar clamps, too.

While bar clamps can be used in metalworking, too, this is a blog piece about woodworking, so we won’t address that use.  However, bar clamps are also used to hold pieces of wood while they are being cut or shaped, and in those uses, bar clamps do very well.

Cleaning and Hanging Bar Clamps

As with all tools and equipment in your shop, bar clamps need to be kept clean in order to function properly. 

A dry cloth will work well to keep dust and debris from building up on all of the parts of your bar clamp.  This will keep it functioning properly and not damage or stain the workpieces being clamped. 

A little oil on all of the moving parts will make it easy to adjust and keep rust from developing along the metal bar, too.

Bar clamps should be hung in a dry place in your shop.  Hanging keeps them both handy and out of the way. 

It’s your woodworking shop and presumably fitted with all necessary tools for the tasks you undertake.  Making a DIY rack for your bar clamps can be a pretty easy project. 

For instance:

  • Screw some PVC pipe under your workbench and hang the bar clamps from it.
  • Cut scrap 2 x 4 into pieces and screw them to your wall just far enough apart so your bar clamps can fit in between suspended by them.
  • Make a towel rack to hang your bar clamps out of some 2 x 4 scraps and a dowel strong enough to hold them.

Helpful Bar Clamp Videos

Although this video addresses various types of clamps, it does have good information about bar clamps.  Check it out here.

If you are really ambitious, make your own.  Here’s a video that offers one way to do just that.

Pricing for Bar Clamps

We poked around various online sources for you and found decent bar clamps come in a wide range of price points. 

A 48” bar clamp can be had for as little as $40; a two clamp set of 24” and 48” for $140; and a 6-piece set of various sizes for $200.

Bessey KREK2440 REVOlution Clamp Kit

As we mentioned, bar clamps can be expensive.  But, again, they can be indispensable in a woodworking shop that tackles new tabletops, cabinets, and drawers.  If you are going to spend up for a set, keep in mind the cleaning and hanging suggestions above.

Every cabinet maker shop will have bar clamps in various sizes, as they should.  If your projects are going to include them, or a new dining room table, or any heavy duty blue-ups, you’ll want a good set, too.